Cutterhead with regrindable inserts

Abstract

A rotary cutting tool wherein the positioning of a cutting insert is accomplished via a frontal reference surface instead of a backing reference surface. This is done by modifying the regrindable insert to include a pair of lateral shoulders that must be seated on the reference surface to ensure proper positioning of the insert relative to the cutting tool. The insert is retained against centrifugal dislodgment by the frontal reference surface during rotation of the tool, thereby permitting the latter to be operated at higher rotational speeds. The use of a frontal reference surface also eliminates the need of having to reposition the cutting tool vis-à-vis the workpiece between each sharpening operation of the cutting insert.

1 . A rotary cutting tool, comprising a cutting insert having a forwardly projecting end portion defining a cutting edge and a pair of shoulders extending laterally outwardly relative to said forwardly projecting end portion, an insert mounting member having an axis of rotation, said insert mounting member defining a seat for removably receiving said cutting insert, said seat being provided at a front end thereof with a pair of spaced-apart positioning members for receiving said forwardly projecting end portion of said cutting insert therebetween with said shoulders resting on said positioning members so as to provide centripetal locking of said cutting insert in said seat during rotation of said insert mounting member about said axis of rotation thereof, and a securing structure for releasably securing said cutting insert in said seat.  
     
     
         2 . A tool as defined in  claim 1 , wherein said positioning members are engaged with said cutting insert on at least two different planes.  
     
     
         3 . A tool as defined in  claim 2 , wherein said two planes are arranged relative to said axis of rotation to provide axial and radial restraint of said cutting insert.  
     
     
         4 . A tool as defined in  claim 1 , wherein at least one of said positioning members has two abutment surfaces for engagement with corresponding surfaces of one of said shoulders to restrain said insert against axial and radial translation.  
     
     
         5 . A tool as defined in  claim 4 , wherein another one of said positioning member is adapted to block said insert against rotation.  
     
     
         6 . A tool as defined in  claim 1 , wherein said cutting insert is provided in the form of a plate-like member having a pair of planar and parallel side faces, and wherein said securing structure exerts a compression force against one of said side faces in a direction normal thereto.  
     
     
         7 . A tool as defined in  claim 1 , wherein a plurality of seats are distributed about a periphery of said insert mounting member for releasably receiving corresponding cutting inserts.  
     
     
         8 . A cutting insert setting system for a rotary cutting tool, said cutting insert setting system comprising an insert having a regrindable front surface defining a cutting edge, an insert mounting member having an axis of rotation and defining a seat for receiving said insert, said seat defining at a periphery of said insert mounting member a frontal reference structure against which said regrindable front surface of said insert abuts to set the position of said insert and resist centrifugal dislodgment thereof from said seat during rotation of said insert mounting member.  
     
     
         9 . A system as defined in  claim 8 , wherein said regrindable front surface includes an abutment surface extending laterally outwardly relative to said cutting edge.  
     
     
         10 . A system as defined in  claim 9 , wherein said abutment surface is formed by two shoulders disposed on opposed sides of said cutting edge.  
     
     
         11 . A system as defined in  claim 8 , wherein said frontal reference structure includes at least two abutment surfaces extending in different planes for engagement with corresponding regrindable abutment surfaces on said insert.  
     
     
         12 . A system as defined in  claim 11 , wherein said at least two abutment surfaces of said frontal reference structure are arranged relatively to said axis of rotation to provide axial and radial restraint of said insert.  
     
     
         13 . A system as defined in  claim 12 , wherein said at least two abutment surfaces of said frontal reference structure includes first, second and third abutment surfaces for blocking the insert against translation in two different directions and against rotation about an axis normal to said directions.  
     
     
         14 . A system as defined in  claim 13 , wherein said second and third abutment surfaces are provided on a first positioning member, whereas said first abutment member is provided on a second positioning member, said cutting edge extending between said first and second abutment members.  
     
     
         15 . A cutting insert for use on a rotary cutting tool, comprising a plate-like member having a forwardly projecting end portion defining a cutting edge and a pair of positioning shoulders extending laterally outwardly on opposed sides of said front cutting edge.  
     
     
         16 . A method of setting a cutting insert on an insert holder of a rotary cutting tool, the method comprising the steps of: providing an insert holder having a seat defining a frontal reference surface, providing a cutting insert having a cutting edge and a pair of shoulders, positioning said cutting insert in said seat by abutting said shoulders against said frontal reference surface, and releasably securing said cutting insert in position.  
     
     
         17 . A method as defined in  claim 16 , further comprising the steps of removing said cutting insert from said seat, sharpening said cutting insert by removing a desired thickness of material from said cutting edge, removing the same thickness of material from said shoulders, positioning said cutting insert back in said seat with said shoulders abutting against said frontal reference surface.  
     
     
         18 . A method as defined in  claim 16 , wherein said frontal reference surface includes radial and axial restraining segments, and wherein the step of positioning the cutting insert in the seat is effected by abutting said shoulders against said radial and axial restraining segments so as to provide centripetal locking of the cutting insert in the seat during rotation of the insert holder about an axis of rotation thereof.